1989 Fiscal Year Final Research Report Summary
On line digital manipulation process of elastically and inelastically scattered electron signals in scanning transmission electron microscopy
| Project/Area Number |
63850078
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
電子機器工学
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| Research Institution | Nagoya University |
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Principal Investigator |
HIBINO Michio Nagoya Univ., Engineering, Professor, 工学部, 教授 (40023139)
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| Co-Investigator(Kenkyū-buntansha) |
HANAI Takaaki Nagoya Univ., Engineering, Assistant Professor, 工学部, 講師 (00156366)
SUGIYAMA Setsuko Nagoya Univ., Engineering, Research Associate, 工学部, 助手 (00115586)
SHIMOYAMA Hiroshi Nagoya Univ., Engineering, Associate Professor, 工学部, 助教授 (30023261)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Scanning transmission electron microscopy / Elastically scattered electron / Inelastically scattered electron / Digital processing system / Electron signal manipulation / Specific contrast / Noise elimination |
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| Research Abstract |
1. Improvement of electron detection An electron detector of high sensitivity was investigated for conventional powdered phosphor scintillator of various thicknesses. The scintillator of 0.07mm thickness was found to give the maximum sensitivity at 1OOkV. It was found as well that a YAG single crystal scintillator of lmm thickness gives the sensitivity 4 times as much as the powdered phosphor scintillator. A high-accuracy detection of inelastically scattered and unscattered electroits was realized by installation of a deflection magnet for signal electrons and an aperture diaphragm, to avoid the influence of X ray and stray electrons.
2. Digital processing system of image signals A system was developed to record electron signals of up to three kinds with high- accuracy. Special attentions were paid to acquisition error in sampling and the error was reduced within 0.2% by using a Butterworth filter to avoid aliasing.
3. Digital manipulation process A proper window of low-pass filter was investigated for improvement of resolution without artifacts by using a method combined by filtering and deconvolution. It was found that the resolution is improved by 40% under the appropriate condition. The quantitative evaluation of normalization process of signal electrons by incident electrons was carried out and it was found that the SN ratio is improved in accordance with the theory. The manipulation among elastically scattered and inelastically scattered electrons revealed that the contrast in proportion to atomic number is obtained in the ratio image and that the contrast of structure of specific element is diminished or enhanced in the difference image by taking an appropriate difference factor.
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